For my understanding, supporting apex certificates is a quite basic feature that should be supported out-of-the box!
So basically, for now, Microsoft Managed Certificates are not very useful.
For reference, i'm using successfully https://github.com/shibayan/appservice-acmebot:
This function provide easy automation of Let's Encrypt for Azure App Service. This project started to solve some problems.
✔ Support multiple app services
✔ Simple deployment and configuration
✔ Robustness of implementation
✔ Easy monitoring (Application Insights, Webhook)
They can manage multiple App Service certificates with single Function App.